Self-aligning contact



March 26, 1946. w, cum-1s 2,397,246

SELF-ALIGNING CONTACT I Filed June 30, 1943 jfifiefiiari Wed 6547725,

M zy/ Patented Mar. 26, 1 946 "UNITED :smres PATENT I OFFICE Fred'WLCurtis," Chicago, Ill assignor to I'vano, Inc.,ja corporation ofIllinois ApplicaticnJune 30, 1943,.Seria1Nn. 492,'855 3 Claims. (.01.200-166) This invention "relates to a self-aligning contact, and moreparticularly =to=an improvement'in a .circuitibrea'ker element designed-for use in the ignition system of an internal combustion engine.

One feature of this invention is-that it provides an improvedself-aligning elementadapted to -maintain proper contact relationshipwith another circuit breaker'e'lement; another feature of this inventionis that it permits the freedom of movement desirable to maintain goodelectrical contact with another cooperating contact, while providing animproved electrical conducting path between the movable contact elementand its supporting member; yet another feature of this invention is thatit obviates difiicu'lty with dirt and moisturebetween the portionsforming the universal mounting; and a further feature of this inventionis that it provides a fixed circuit breaker element of reduceddimensions. Other features and advantages of this invention will beapparent from the following specification and the drawing, inwhich'z-Figure 1 is a "side elevation of one embodiment of'a self-aligningcontact unit; Figure 2 is atop planview' of the device shownin Figure 1;Figure 3 isapartial vertical sectional-view of such device, along theline 3-3 of Fi m'e Eh-Figure 4 is atop plan view" of-the supporting studwith the contact element and spring removed; and is a horizontalsectionalview' along the line 5 5 of Figure'B;

Self-aligning points, wherein both contacts have fiat surfacesandone-ofthe-contact elements has limited universal movement to insureproper contact with the other element, have had considerable commercialsuccess in difficult ignition breaker point applications, :as in trucksand other heavy engines. Such pointsare being manufactured and sold bythe 'assignee of' this application in accordance with the disclosure ofJanser Patent 2,214,530, of September 10, 1940, and such points haveproved highly satisfactory except in a few applications.

Under conditions where there is an excessive amount of dirt and greaseon and around the breaker points, and a large amount of moisture, it hasbeen found that occasionally a particle of dirt works in between theinterengaging supporting surfaces, which have heretofore been partialspherical surfaces generated about the same center. When this occurs itenables moisture to get between these supporting surfaces and the dirtand moisture cause arcing and contact difficulties between the movableelement and its support.

The present invention is an improvement on self-aligning breaker pointsof ithe'kindxshownzln the aforementioned Janser patent; and thisapplication is directed entire'ly to an improved construction andarrangement of the cooperating .porti'ons'torming a mounting forthe-movable element. More particularly,. the arrangement issuch that theconvex and concavezportions engageleach other only over an annularsurface, there sbeing a pocket withinithe confines defined by'this en-.ga-gement wherein-dirt and'moisture mayl-raccumulate; and thearc oftheconcave portionis re duced, to improve the supporting:GOHtfliCtjTWhEl-ZB it is. only annular and:to:"reducethe-:alleovervdimensionscftheunit;

Only one unit of the twocooperating' breaike point units isshow-n in thedITBiWiHgfOfJZhETDEESEHt a plication, inasmuch, as two such unitsoperative circuit and: an actuating arrangement is illustrated in Figure1 0f .the aboveementioned Janser patent, to which reference may bemadefor a more. complete description :of the-general operation ofself-aligning breaker points: of the .kind :here .disclosedi.Generallypthe fixed-contact icaveportion havingza surface .13.The-description of? the .outer' surface 1-2;. assloping. :outwardlysand-downwardlycis, of'coursawith reienenbewto the portions shown in theaccompanying'rdrfiwing; and such description is to be construed inaccordance with the particular position in which the contact unit may beplaced in actual operation. Moreover, while the supporting member ishere illustrated as a stud adapted to be screwed into a threaded openingin a plate in the distributor, it may be of any other common type, asfor example a rivet adapted to be mounted in the distributor plate or inthe breaker arm.

In the particular embodiment of the support ing member illustrated inthe accompanying drawing, an upwardly extending convex portion I4 isprovided. This portion is in the form of a.

truncated partial spherical shape, the radius of curvature being thesame as that of the concave I portion and the centers being concentricwhen the parts are in operative relation. The truncated arrangement isbest shown in Figure 3,

that only an annular external partial spherical surface,.l.5 remains tomake engagement with the surfac of ,lthe concave portion I 3. V Beneaththis convex portion M, the supporting member is proder, and below thisshoulder it tapers downwardly a threaded shank portion l8.

In orderto maintain the two members in proper and desired relationshipduring operation while permitting limited universal movement of the 1contact element [0, a'ring IQ of spring metal is provided. This ringencircles a portion of both of 1 said members, its upper part contactingthe surface Won the movable element l and its lower I part contactingthe surface-I6 on the supporting stud. The downwardly and inwardlysloping ar- .rangement of the surface 16 causes. the edge of the ringcontacting it to always tend to move downwardly, so that the springaction of the ring tends to always urge the two members together;pandthe fact that the, surface [2 is' a partial spherical surface aboutthe same center as the twosurfaces forming the swivelable supportenwhere it will beseen that the upper part of the I spherical surface iscut ofi or ground away, so 1 i vided with an annular outwardly extendingshoulables easy movement of the'contact element Ill within'the' upperend of the spring. The form of spring'ring shown has a solid annularupper portion'and lower finger portions. These lower portions arearched, so that both edges of the ring have a lesser diameter than thecentral part 1 thereof The separation between the lower finger portionsenables a substantial change of diameter I of this lower portion withoutdistortion of the metalibeyondits elastic limits, so that the ring 'may'beslipped down over the parts during sembly; i

:tions; Any hard particles or moisture working in between the annularsupporting surfaces tends to keep on working in and to accumulate in thepocket thus provided. a Any dirt thus accumulated m'erely'remainsin thepocket'without creating anydifliculties; and moisture therein dries outas soon as the excessively moist conditions no longer exist.

space isat a premium.

concave portion now only subtends a central f spherical angle ofaboutwhereas previous arrangements of this kind have subtended central anglesclosely approaching. ..This reduction in the centralfl sphericalj anglesubtended not only reduces wear ontheooperating surface wherethere'is'only an annular engagement, by

getting the slope further away from the vertical,

but also enables a reduction in the over-all height ofthecontact,element, the height from the portion 11 to'the contact face I I.

This is of considerable advantage in certain applications where While Ihave shown and described certain embodiments of my invention, it is tobe understood that it is capable of many i modifications.

Changes, therefore, in the construction and arrangement may be madewithout departing from the spirit and scope of the invention asdisclosed in the appended claims; 1 'j a; L

Iclaim: 1 i f x 1. Apparatus of the character described, including; acontact member having a body'portion 'and a contact face; a supporting,member adapted rangement being such thatsaid; portions-make only anannular contact, although one of appreciable width, and such that'thereisa closed pockat between said portions within: the confines of saidannular contact; and means for maintaining said membersinthe desiredrelationship.

2. Apparatus of the character described, in-

vcludingzja contact member having a body portion and a contactface; asupporting member adapted to engage said body-portion tosupport saidcontact member for limited universal'movement, one of said membersh'aving; aconcave partial spherical portionand theother having atruncated convex partial spherical solid portion having a depression inthe center thereof, forming a closed pocket of substantial sizerelativetothis portion, the radii of said portions-being-thei same,whereby said portions-make only an' annular contact, but whereintheannularcontactareais of substantial width; and means for:mairgtaining said members in thedesired relationship.

3. Apparatus of the charactereclaimed in claim 2, wherein saidconcaveportion subtends acen tral spherical angle of only about '1 20,;11 p 1mm; eens.)

